Wecht said investigators are working through a three-tier process that includes forensic, non-forensic and electronic evidence.

Collection of blood, bullet fragments, footprints and fingerprints can be analyzed fairly quickly, according to Wecht, but he said the non-forensic evidence can be a lengthy process because it involves connecting relationships between the victims and the people they knew "through interrogation and searching out people and interrogating them, and sometimes going back to them and correlating stories."

"Then you begin to put it together. That could take time," Wecht said. "And then some people may have left town, so you have to work with authorities elsewhere to identify people who may be on the move."

Police have said that two men teamed up to ambush a backyard cookout on Franklin Avenue and methodically shot Brittany Powell, Jerry Shelton, Shada Mahone, Tina Shelton and Chanetta Powell, who was eight months pregnant.

In Wecht's opinion, District Attorney Stephen Zappala sold residents a false sense of security by telling them they're safe while the gunmen are potentially still at large.

"I don't see how and why the district attorney can go out into the community -- and nobody has been charged -- and say that you are safe. How do you know?" Wecht said. "And there is one survivor. How do you know they're not going to come back for that survivor and his friends?"